Enable support for very old legacy flat binaries

configname: CONFIG_BINFMT_FLAT_OLD

Linux Kernel Configuration
└─>Executable file formats
└─>Enable support for very old legacy flat binaries
In linux kernel since version 5.1 (release Date: 2019-05-05)  
Support decade old uClinux FLAT format binaries. Unless you know
you have some of those say N here.